CN101396569B - Composite hydrogel using organism tissue as bracket, preparation method and use thereof - Google Patents

Abstract

The present invention relates to a kind of composite hydrogel, its preparation method and its use, more specifically, the present invention relates to a kind of novel composite hydrogel with biological tissue as scaffold, and the method for preparing the composite hydrogel, wherein The method comprises the following steps: firstly obtain a biological tissue with a regular network structure from a biological body, and then soak it in an aqueous solution containing monomers for a certain period of time, thereby introducing monomers into the network structure of the biological tissue , followed by polymerization and crosslinking of the monomers, resulting in composite hydrogels with superior properties. The composite hydrogel of the present invention is a combination of biological gel and synthetic gel, not only has the regular microstructure of biological gel, but also has the characteristics of relatively stable performance of synthetic gel and not easy to biodegrade. In addition, the composite hydrogel of the present invention has high mechanical strength and has broad application prospects in fields such as industry and biomedicine.

Description

Composite hydrogel with biological tissue as scaffold, preparation method and application thereof

technical field

The invention relates to a composite hydrogel, its preparation method and its use.

Background technique

Hydrogels have been a research hotspot in the last twenty or thirty years. Many hydrogels have been synthesized and applied in the field of production and life. However, synthetic hydrogels generally have the shortcomings of irregular structure and uneven distribution of molecular chains. These shortcomings make the synthetic hydrogels unable to compare with natural hydrogels (such as some organs and tissues of the human body) in terms of strength, and the swelling is slow. And the recovery performance after swelling is not good, so its application is greatly limited. Therefore, the synthesis of regular structure hydrogels has attracted the interest of researchers.

Hydrogel is a kind of material form ubiquitous in nature. The agar, konjac, and jelly that people often come into contact with are all gel substances. The water content of some marine organisms such as jellyfish and sea anemones is as high as 90%, but their bodies still have high mechanical strength and can respond quickly to environmental stimuli. The main substance that makes up these marine organisms is hydrogel. Some soft tissues in the human body (such as tendons, ligaments, meniscus cartilage, etc.) are also composed of gel substances. These tissues have the characteristics of softness, toughness, impact resistance, low friction, and good permeability. However, the current artificial biological tissues (such as artificial hearts, artificial joints, etc.) are all made of solid materials (such as metals, ceramics), which have high mechanical strength, but do not have the aforementioned advantages of human tissues, and have poor compatibility with the human body. . If a hydrogel with properties close to that of human soft tissue and good compatibility with human body can be prepared, it will be a better choice to use them to replace damaged soft tissue. But the main problem now is that artificial hydrogels cannot compare with biological gels in terms of mechanical properties and response speed. Because the regularity of the structure of the biological hydrogel is beyond the reach of the current common synthesis methods. It is currently believed that its regularity is based on the regular arrangement of cells, which is difficult to do artificially.

In recent years, through the joint efforts of scientific researchers, some progress has been made in the synthesis of hydrogels with regular structures. Among them, the freezing-thawing method (also known as "cycle freezing method") is a method for preparing hydrogels by physical crosslinking, and the PVA (polyvinyl alcohol) hydrogels prepared by this method can be used at higher water contents. It has good mechanical properties. In 2005, Tanaka and Gong Jianping "Novel hydrogels with excellent mechanical performance." (Progress in Polymer Science, 2005.30(1): p.1-9.) reviewed several hydrogels with high strength and relatively regular structure, including : Topological hydrogel (TPgel), nanocomposite hydrogel (NC gel) and double network hydrogel (DN gel). Not only that, through the regularization of the structure, the recovery performance of the hydrogel can be improved, and it can even have some special properties. Okumura et al. "The polyrotaxane gel: a topological gel by figure-of-eight cross-links." (Advanced Materials, 2001.13(7): p.485-487.) The topological gel first synthesized and named, is a A hydrogel with "8"-shaped supramolecules acting as cross-linking points. The polymer chains of this gel have bulky end groups and are linked together by supramolecules with a figure-eight topology acting as cross-linkers. When a force is applied, these cross-linked supramolecules slide freely on the modified polymer chains, so that the distance between the molecular chains is relatively uniform, and the mechanical properties are greatly improved. Haraguchi et al. "Nanocomposite hydrogels: aunique organic-inorganic network structure with extraordinary mechanical, optical, and swelling/deswelling properties." (Advanced Materials, 2002.14(16): p.1120-1124.) Use inorganic clay nanoparticles as cross-linking points, The monomer N-isopropylacrylamide (NIPAAm) was polymerized on the surface of nanoparticles to prepare a nanocomposite gel (NC gel) with high mechanical strength. This gel interacts with the surface of clay particles through long polymer chains to ensure that the initiation of polymer chains starts from the surface of the clay sheet. Since the clay particles are evenly distributed in the system, they are stacked together more regularly. The distance between clay particles is basically the same, so the distribution of macromolecular chains prepared by this method is relatively uniform, and the structure is relatively regular.

"Double network hydrogels with extremely mechanical strength" (Advanced Materials 2003, 15, 1155-1158.) reported the preparation and structural properties of a double network (DN) hydrogel with high mechanical strength. The double-network method means that a three-dimensional network (such as a PAMPS network) with a relatively high cross-linking density is first prepared by free radical polymerization as the first network of the system, and then the network is added to another monomer (such as AAm) and Swelling in an aqueous solution of the cross-linking agent initiates polymerization again to prepare a network with a lower cross-link density or even no cross-links. The two three-dimensional networks penetrate each other, which greatly improves the mechanical properties of the system, and its compression resistance can be increased by dozens to hundreds of times.

The inventors of the present invention used the polymer microspheres that were irradiated in advance to be connected with peroxide groups as initiators and crosslinking agents, so that the monomers could initiate system polymerization at a certain temperature, and obtained macromolecular microspheres with high mechanical strength. Composite (MMC) hydrogel (Huang T, Xu HG, JiaoKX, Zhu LP, Brown H R, Wang H L.A Novel hydrogel with high mechanical strength: a macromolecular microsphere compositehydrogel. Adv. Mater.2007.19(12): p.1622- 1626.).

Because supramolecular self-assembly can form molecular membranes with unconventional structures, it is very valuable to synthesize high-strength hydrogels with regular structures. Tang et al. "Nanostructured artificial nacre." (Nature Materials, 2003.2(6): p.413-418.) used the alternate deposition method to obtain an inorganic/organic composite layered structure. The strength of this composite membrane material can be compared with that of human bones. Comparable. Since the Alternate Layered Assembly (LBL) technology is a gradual process like the growth sequence of organisms, the synthetic hydrogel obtained by this method has a regular structure of layer-by-layer stacking. Self-assembly technology is often used in the synthesis of protein gels. First, the polypeptide chains are folded, and then self-assembled into the hydrogel system to obtain many hydrogels with special response properties. Recently, Um et al. "Enzyme-catalysed assembly of DNA hydrogel." (Nature Materials, 2006.5(10): p.797-801.) assembled a DNA hydrogel with a controllable shape and a regular structure using a special DNA chain. The shape of the hydrogel can be controlled, and it is completely biodegradable and biocompatible, and has application prospects in artificial tissues, drug sustained release, and cell engineering.

As mentioned above, hydrogel has broad application prospects in artificial muscle tissue, so a very important purpose of hydrogel research is to serve as a substitute for biological tissue. It can be seen that a large number of natural polymer materials are currently used in the preparation of hydrogels, which can be roughly divided into the following categories: anionic polymers, such as: hyaluronic acid, alginic acid, angle glue, chondroitin sulfate, glucan Sugar sulfate and colloid, etc. Cationic polymers such as chitosan and polylysin. Amphoteric polymers such as collagen (gelatin), carboxymethyl chitin, and fibrin. Neutral polymers such as dextran, agar, konjac mannan and starch.

Biological tissues are mainly composed of proteins and sugars, among which collagen plays a pivotal role in living organisms because it is the main component of the ECM (extracellular matrix) protein that maintains the shape of biological tissues. At the same time, it is known for its low antigenicity and porosity, and is easy to biodegrade, so it is widely used in tissue engineering. Because of its low antigenicity, it has very good biocompatibility, and because of its porosity, it facilitates the entry of cells and the enrichment and delivery of oxygen and nutrients, and can be used for cell culture. One of the current research goals of general biomaterials is to prepare temporary scaffolds to support the formation of new tissues. Because of its excellent biocompatibility, collagen is the main component of human arteries, so it plays an extraordinary role in the synthesis of artificial blood vessels. People graft collagen on a variety of materials, including polymers such as polypropylene (PP), polyurethane (PU), and various fibers to increase their biocompatibility. At present, the collagen used by people mainly comes from cattle, pigs, rabbits and other animals, the main type of which is type I collagen, and a small amount of type III collagen. The substance that constitutes the jelly layer of jellyfish contains more type II collagen. Type I collagen mainly exists in the skin, tendons and ligaments, and has strong tensile strength; Type II collagen exists in cartilage and vitreous body, and has the ability to resist compression; Type III collagen is more common in tissues with large stretchability. Such as loose connective tissue, etc., have stretchability and strain. Song "Collagen scaffolds derived from a marine source and their biocompatibility." (Biomaterials 2006, 27, 2951-2961) found that collagen extracted from jellyfish has better biocompatibility than collagen (gelatin) derived from other animals sex. Their research on marine biological collagen has applied for a patent (KR2006091350)

Collagen is easy to form pores, and can obtain 2D (two-dimensional) and 3D (three-dimensional) structures by changing its preparation conditions, which can be applied to tissue engineering. Kang et al. "Coculture of endothelial and smooth muscle cells on acollagen membrane in the development of a small-diameter vasculargraft." (Biomaterials 2007, 28, 1385-1392) first used chemical cross-linking to make gelatin gel, and then in different Freeze-thaw under the environment to obtain one-dimensional, two-dimensional and three-dimensional regular hydrogels that can be completely biodegradable. Now collagen mainly comes from cattle, pigs, rabbits and other animals.

As for the research on the direct combination of organisms and chemical substances as gel materials, there are few reports. Mang et al. (US20040170663A1, US20070048291A1) grafted polymer chains onto cartilage to modify biological tissues such as cartilage to increase their strength.

The utilization of biological tissue involved in the present invention is fundamentally different from the reported research work. First of all, the present invention directly uses biological tissues with regular microstructures as scaffolds to prepare hydrogels, instead of using collagen extracted from living organisms to prepare hydrogels. The invention directly utilizes the regular structure of the biological tissue, so that the prepared hydrogel has the inherent advantage of the biological body—regular microstructure compared with the hydrogel of the same material. Secondly, compared with the hydrogel obtained similarly to the preparation method of the present invention, that is, the hydrogel obtained by introducing another gel system in a gel system, such as the DN hydrogel of Gong Jianping et al. ( WO2002057368A1), this type of hydrogel also has advantages: the first network used by the inventors of the present invention has regular microstructure and high mechanical strength, while the first network used by Gong Jianping et al. is completely disordered, so This type of hydrogel is more regular in structure than the hydrogel prepared by the predecessors, and its performance also has certain advantages. When the water content of DN hydrogel is 90%, the elastic modulus is 0.3MPa, and its compressive fracture strength is about 10MPa. However, most of these composite hydrogels (with a water content of about 85%) do not break during the compression mechanical performance test, and the compressive strength reaches more than 10 MPa when the compression ratio is 95%. In addition, compared with other methods for synthesizing high-strength hydrogels, this method also has its unique advantages. No matter whether NC hydrogels, MMC gels or self-assembled hydrogels with superior performance, the preparation process has no The preparation of such composite hydrogels with biological tissues as scaffolds is easy. Finally, in terms of chemical residues, the hydrogel with biological tissue as a scaffold is relatively low, which will be more conducive to the application of this type of hydrogel in the fields of biomedicine and tissue engineering. All in all, the inventors of the present invention have developed a brand-new application method of biological tissues, and obtained a new type of composite hydrogel with broad application prospects.

Contents of the invention

An object of the present invention is to provide a novel composite hydrogel, which is prepared by using biological tissue as a scaffold and polymerizing water-soluble monomers diffused in the scaffold. The present invention prepares The composite hydrogel utilizes the regular structure of biological tissues to obtain a regular structured composite hydrogel.

Another object of the present invention is to provide a method for preparing a composite hydrogel with biological tissue as a scaffold, wherein the biological tissue selected, separated and cut into a suitable shape is directly used as a scaffold, and then soaked in In an aqueous solution containing a certain concentration of monomers, the immersion time is long enough so that the monomers and cross-linking agents can be fully diffused in biological tissues, and finally cross-linked and polymerized by an appropriate method to obtain a composite hydrogel. The hydrogel preparation method has considerable universality, and can be applied to most biological tissues and corresponding water-soluble monomers with a regular three-dimensional network structure.

In one aspect of the present invention, a composite hydrogel is provided, including biological tissue as a scaffold and polymer chain compounds distributed in the biological tissue scaffold.

In one embodiment, the biological tissue is derived from the tissues or organs of marine molluscs or terrestrial animals with regular structures.

In a preferred embodiment, the biological tissue is a collagen part of a jellyfish or a peeled sea cucumber body with a regular structure.

In one embodiment, the polymer chain compound is formed by polymerizing a water-soluble monomer in an aqueous solution.

In a preferred embodiment, the monomer is selected from: neutral monomers such as acrylamide and its derivatives, N-vinylpyrrolidone, hydroxyethyl acrylate, vinyl methyl ether; anionic monomers such as acrylic acid and Its derivatives, crotonic acid, 2-acrylamide-2-methylpropanesulfonic acid, acrylic propanesulfonic acid; cationic monomers such as methacryloylethoxy quaternary ammonium chloride, vinylpyridine.

In one embodiment, the aqueous solution further includes a water-soluble cross-linking agent that matches the monomer, and the water-soluble cross-linking agent is selected from N, N'-methylenebisacrylamide, ethylene glycol, Polyethylene glycol, succinic acid or adipic acid.

In another aspect of the present invention, there is provided a method for preparing a composite hydrogel with biological tissue as a scaffold, comprising: immersing the biological tissue as a scaffold in an aqueous solution dissolved with a water-soluble monomer, making the The water-soluble monomer is diffused into the biological tissue, and then the water-soluble monomer is polymerized to form a polymer chain compound interspersed in the biological tissue, thereby obtaining the composite hydrogel.

In one embodiment, the biological tissue is derived from the tissues or organs of marine molluscs or terrestrial animals with regular structures.

In a preferred embodiment, the biological tissue is a collagen part of a jellyfish or a peeled sea cucumber body with a regular structure.

In one embodiment, the polymer chain compound is formed by polymerizing water-soluble monomers in aqueous solution.

In a preferred embodiment, the monomer is selected from: neutral monomers such as acrylamide and its derivatives, N-vinylpyrrolidone, hydroxyethyl acrylate, vinyl methyl ether; anionic monomers such as acrylic acid and Its derivatives, crotonic acid, 2-acrylamide-2-methylpropanesulfonic acid, acrylic propanesulfonic acid; cationic monomers such as methacryloylethoxy quaternary ammonium chloride, vinylpyridine.

In one embodiment, the aqueous solution further includes a water-soluble cross-linking agent that matches the monomer, and the water-soluble cross-linking agent is selected from N, N'-methylenebisacrylamide, ethylene glycol, Polyethylene glycol, succinic acid or adipic acid.

In a preferred embodiment, the concentration of the monomer is between 0.5-4M, and the concentration of the cross-linking agent is 0-5.0 mol% of the concentration of the monomer.

In a preferred embodiment, the method for polymerizing and cross-linking monomers in biological tissues to form polymer chain compounds includes radiation-induced polymerization and cross-linking (abbreviation: radiation method) and chemically-initiated polymerization and cross-linking (abbreviation: chemical method).

In a preferred embodiment, the high-molecular chain compound is formed in the biological tissue by irradiation method, wherein γ-rays produced by high-energy radiation source ⁶⁰ Co and high-energy electron beams produced by electron accelerators are used to implement the irradiation, and by irradiation The high-energy rays polymerize and cross-link the monomers (optionally in the presence of a cross-linking agent) in the biological tissue, thereby preparing the composite hydrogel.

In a further preferred embodiment, when the high-energy radiation source is gamma rays produced by ⁶⁰ Co to prepare the composite hydrogel, the irradiation dose is 5-60 kGy, and the irradiation time varies with the dose rate.

In a preferred embodiment, the composite hydrogel is obtained by chemically initiating monomer polymerization in soaked biological tissue. Wherein, by adding an initiator such as APS (ammonium persulfate)/NaHSO ₃ system, triggering the polymerization of the monomer in the biological tissue at 0-40 ° C to form a polymer chain compound in the biological tissue, thereby producing The composite hydrogel.

Compared with the single hydrogel without biological tissue prepared under the same conditions, the composite hydrogel of the present invention has many superior properties, such as high mechanical strength, good recovery performance and more responsiveness.

In yet another aspect, this aspect provides the application of the above composite hydrogel or the composite hydrogel obtained by the above method in the preparation of artificial biological tissues.

In a preferred embodiment, the artificial biological tissue is selected from: artificial tendon, artificial ligament, artificial meniscal cartilage, artificial heart or artificial joint.

Description of drawings

Other features and advantages of the present invention will become more apparent from the detailed description with reference to the accompanying drawings, in which:

Fig. 1 (a)～(b) shows the SEM (scanning electron microscope) photograph of the microstructure of collagen in the jellyfish;

Fig. 2 shows the SEM photo of the PAA composite hydrogel with collagen in jellyfish as scaffold made by irradiation method according to one embodiment of the present invention;

Fig. 3 shows the SEM photo of the PAA hydrogel according to the comparative experiment of the present invention;

Fig. 4 shows the typical compressive stress-strain curves of various samples according to the present invention;

Fig. 5 shows the typical tensile stress-strain curves of various samples according to the present invention;

Figure 6 shows the PAA gel obtained under the irradiation time of 1 h and the monomer concentration of 2M.

Detailed ways

In one embodiment, the present invention provides a composite hydrogel, including biological tissue as a scaffold and polymer chain compounds distributed in the biological tissue scaffold.

In one embodiment, the biological tissue is derived from the tissues or organs of marine molluscs or terrestrial animals with regular structures.

In a preferred embodiment, the biological tissue is a collagen part of a jellyfish or a peeled sea cucumber body with a regular structure.

In one embodiment, the polymer chain compound is formed by polymerizing a water-soluble monomer in an aqueous solution.

In a preferred embodiment, the monomer is selected from: neutral monomers such as acrylamide and its derivatives, N-vinylpyrrolidone, hydroxyethyl acrylate, vinyl methyl ether; anionic monomers such as acrylic acid and Its derivatives, crotonic acid, 2-acrylamide-2-methylpropanesulfonic acid, acrylic propanesulfonic acid; cationic monomers such as methacryloylethoxy quaternary ammonium chloride, vinylpyridine.

In one embodiment, the aqueous solution further includes a water-soluble cross-linking agent that matches the monomer, and the water-soluble cross-linking agent is selected from N, N'-methylenebisacrylamide, ethylene glycol, Polyethylene glycol, succinic acid or adipic acid.

In another embodiment, the present invention provides a method for preparing a composite hydrogel with biological tissue as a scaffold, which includes introducing a monomer into a selected biological tissue, and then under gentle (although It is possible to polymerize and cross-link the monomers under the condition of not destroying the regular structure of the biological tissue to obtain a composite hydrogel containing synthetic polymers with the biological tissue as the scaffold.

The biological tissues selected by the method of the present invention include: animal tissues with a three-dimensional network structure, relatively high water content, and capable of swelling in water. These animal tissues can be most of the mollusk body, such as jellyfish, sea cucumber, etc., or a certain part of the body of other non-mollusk. As shown in Figure 1(a)~(b), the regular microstructure of collagen in jellyfish is shown by SEM photos. From the figure, it can be seen that the hole structure composed of a large number of "chain bundles" and the regular " Arranged layer by layer, it is reasonable to think that it is these fine microstructures that make jellyfish, a natural gel, have the superior properties mentioned above.

The monomers selected in the method of the present invention include: acrylic acid (AA) and its derivatives, acrylamide (AM) and its derivatives, acid anhydrides and other reactive monomers suitable for preparing hydrogels. Soaking biological tissues with an aqueous solution containing a certain monomer concentration requires that the monomer must be water-soluble, that is, any water-soluble monomer can be used to prepare this composite hydrogel. The type and concentration of monomers are an important aspect affecting the performance of hydrogels. The type of monomer is directly related to the performance of the synthesized hydrogel. If N-isopropylacrylamide is used to prepare this type of composite hydrogel, the resulting hydrogel will have temperature sensitivity; A pH-sensitive hydrogel can be prepared; if several monomers are used together, the performance of this type of composite hydrogel will be changed more. At the same time, the monomer concentration of the soaking solution can be changed without destroying the biological tissue. 0.5-5M is a more suitable range. The monomer concentration in this range can be soft and elastic or tough and strong. composite hydrogel. Generally speaking, when the monomer concentration is less than 3M, the obtained composite hydrogel is relatively soft and elastic, and as the monomer concentration increases, the gel gradually becomes stronger. However, the concentration of the monomer cannot be increased indefinitely, and too concentrated a solution will cause dehydration and denaturation of biological tissues.

The addition of cross-linking agent can increase the degree of cross-linking to a certain extent, and under the same conditions, the addition of cross-linking agent helps to improve the strength of the composite hydrogel. However, excessive cross-linking agent will lead to excessive cross-linking of the hydrogel and become brittle. It is proved by experiments that the suitable concentration range of cross-linking agent is between 0-5 mol% of the monomer concentration. The choice of cross-linking agent should match the monomer. For example, when choosing acrylic acid, the corresponding cross-linking agent is N, N'-methylenebisacrylamide.

In order to achieve cross-linking polymerization at normal temperature and pressure, the environmentally friendly and efficient irradiation method was first adopted. Radiation sources used in the irradiation method: ⁶⁰ Co-γ rays, high-energy electron velocities produced by electron accelerators, etc. (irradiation dose is 5-60kGy). The size of the radiation dose directly affects the performance of the hydrogel. The irradiation time depends on the dose rate. When the same dose rate and other conditions are the same, the shorter the irradiation time, the lower the degree of crosslinking, the product is soft and elastic; on the contrary, as the irradiation time prolongs, the degree of crosslinking increases. , the product becomes tough and eventually becomes hard and brittle.

Although the irradiation method is simple and convenient to apply, the sources of irradiation are not particularly readily available. Such composite hydrogels can also be obtained by chemical methods. When chemical methods are used, how to achieve mild polymerization conditions is another key to the realization of the present invention. The present invention firstly achieves the goal by selecting a suitable initiation system. Compared with the irradiation method, the chemical method needs to add an initiator. The process is to soak the pre-cut biological tissue in a solution containing a certain concentration of monomers and cross-linking agents. After a period of time, add an initiator to it, and then slowly polymerize it at room temperature to prepare a composite hydraulic gel. glue. The effect of cross-linking agent on the performance of composite hydrogel is similar to that of irradiation method.

As mentioned above, as far as the chemical method is concerned, the selection of a suitable initiation system is the key to the success of preparing composite hydrogels. For monomers such as acrylic acid, use conventional thermal initiation systems, conventional thermal initiators (such as ammonium persulfate, potassium persulfate), the decomposition temperature is higher than 40 ° C, which is not suitable for biological tissues denatured at high temperatures . Adding NaHSO ₃ (sodium bisulfite) therein can reduce the activation energy of the reaction, thereby realizing the conditions for polymerization at a lower temperature. For the series of acrylamide monomers, it is also possible to speed up the reaction speed and shorten the reaction time by adding accelerator TEMED (N, N, N', N'-tetramethylethylenediamine).

Example

Example 1: Preparation of PAA composite hydrogel with jellyfish mesogel layer as scaffold by irradiation method

Use tap water and deionized water to wash away the salt of the jellyfish skin (ie, the umbrella part of the jellyfish) bought in the market. Then cut it into a round piece with a diameter of 1.5-2cm, or a square of 2×2cm. After swelling to equilibrium in deionized water, remove the upper and lower epidermis with a blade (the rest is the jellyfish middle glue layer, and its main component is collagen. ). The processed jellyfish mesogelatin block was soaked in a certain concentration such as acrylic acid monomer solution (optionally added as N, N'-methylenebisacrylamide cross-linking agent) for 24 hours, for example, the solution quality was About 6 times of the quality of jellyfish middle glue layer, make immersion completely. Then remove the soaked jellyfish mesogel layer from the soaking solution, and irradiate with ⁶⁰ Co-γ rays (average dose rate 10 kGy/h) to cross-link and polymerize the composite hydrogel. Fig. 2 has shown the SEM photograph of the PAA composite hydrogel that takes the collagen in the jellyfish as the scaffold made by the irradiation method, as shown in Fig. 2, the composite hydrogel obtained by the irradiation method of the present invention keeps the jellyfish collagen Some shapes.

<Comparative Example 1>

Take an appropriate amount of solution containing acrylic acid monomer (optionally adding a cross-linking agent) soaked in the middle glue layer of jellyfish, divide it into penicillin vials, and also irradiate with ⁶⁰ Co-γ rays. The same as the glue, get polyacrylic acid (PAA) hydrogel, as shown in Figure 3.

<Comparative Example 2>

The gel layer in the jellyfish was not immersed in the monomer solution, and was irradiated with ⁶⁰ Co-γ rays for the same time as the composite hydrogel, and the gel layer in the jellyfish maintained the basic shape.

Detailed examples are as follows:

1) Take a piece (2.5g) of the round jellyfish medium glue layer, soak it in 15mL (2.5×6) solution containing acrylic acid and N,N'-methylenebisacrylamide, the concentration of monomer AA is 2M , the amount of cross-linking agent is 0.2% (mole percentage) of AA concentration. The gelatinous layer of the jellyfish was soaked in it for 18 hours, and then transferred to a penicillin vial (covered with the stock solution to maintain the morphology of the gelatinous layer of the jellyfish). Irradiate with ⁶⁰ Co-γ rays (average dose rate 10kGy/h) for 2 hours, and take samples from broken bottles. In addition, the middle glue layer of the jellyfish was cut into strips of 6×6×50 mm, and a strip of composite hydrogel was prepared under the same conditions as above for tensile testing.

Under the condition of 25°C, the compressive strength was tested with an electronic universal testing machine, the beam speed was controlled at 5mm/min, and the tensile properties were tested with Instron3365 at a beam speed of 50mm/min.

The obtained composite hydrogel yielded when the compression ratio was 92% during the compression test, and the breaking strength was 18.5 MPa; the tensile performance test results were: the elongation was 247%, and the breaking strength was 104 kPa. And its comparative example, the PAA gel yielded when the compression ratio was 88.5% during the compression test, and the breaking strength was only 2.93MPa; the tensile performance test results were: the elongation was 229%, and the breaking strength was 12.1kPa. The collagen in jellyfish yielded when the compression ratio was 78.7% during the compression test, and the breaking strength was 0.98MPa. Figure 4 shows the typical compressive stress-strain curves of various samples; it can also be seen from the figure that the compressive strength of the composite hydrogel is much higher than that of AA gel and jellyfish.

2) Take a piece (2.8g) of the round jellyfish medium glue layer and soak it in 17mL of 3M AA (acrylic acid) solution for 18 hours. Then transferred to the penicillin vial (covered with stock solution to keep the shape of the jellyfish mesogelatin), irradiated for 2 hours, and the bottle was broken for sampling. The obtained composite hydrogel did not yield during the compression test, and when the compression ratio was 95%, the compressive strength was 19.4MPa. And its comparative example, that is, PAA gel yields when the compression ratio is 90.3%, and the breaking strength is only 4.82MPa. The strip sample was tested for tensile properties, its elongation was 320%, and its breaking strength was 66kPa, while the elongation of its comparative example was 1200%, but its breaking strength was 36kPa. Figure 5 shows the typical tensile stress-strain curves of various samples. It can be seen that the elongation of the comparative example is large, while the modulus of collagen in the jellyfish is high, and the composite gel combines the advantages of the two, which is A gel that combines flexibility and strength.

3) Other operations are the same as 2), changing the monomer concentration to 2M, and the irradiation time to 1 hour. The water content of the obtained composite hydrogel was 86.3%. The gel did not yield during the compression test, and the compressive strength was 8.6 MPa when the compression ratio was 95%. Figure 6 shows the PAA gel obtained under the irradiation time of 1 h and the monomer concentration of 2M. As shown in Figure 6, in the comparative example, that is, PAA gel, it is soft and not moldable, and has almost no strength at all, so it cannot be tested.

4) Other operations are the same as 3), except that the irradiation time is 2 hours. The water content of the obtained composite hydrogel was 85.8%, the gel did not yield during the compression test, and the compressive strength was 13.6MPa when the compression ratio was 95%. And its comparative example, that is, PAA gel yields when the compression ratio is 80%, and the breaking strength is only 0.35MPa.

5) Other conditions are the same as 2), and the irradiation time is 3 hours. The obtained composite hydrogel has a water content of 84.3%, yields at a compression ratio of 90.4%, and a fracture strength of 7.84MPa. And its comparative example, that is, PAA gel yields when the compression ratio is 92.5%, and the breaking strength is only 2.65MPa.

6) Other conditions are the same as 2), except that the concentration of the acrylic acid solution is changed to 4M. The obtained composite hydrogel did not yield during the compression test, and when the compression ratio was 95%, the compressive strength was 28.8 MPa. While in the comparative example, that is, the PAA gel yielded at a compression ratio of 81.2%, the breaking strength was only 1.79 MPa.

7) The other conditions are the same as 1), that is, the concentration of the acrylic acid solution is 2M, the dosage of the crosslinking agent is 0.1% (molar percentage) of the monomer concentration, and the irradiation time is 2 hours. The obtained composite hydrogel did not yield during the compression test, and the compressive strength was 13.9 MPa when the compression ratio was 95%. The tensile performance test results are: the elongation is 306%, and the breaking strength is 74.3kPa. And its comparative example, that is, PAA gel yields when the compression ratio is 77% during the compression test, and the breaking strength is only 0.31MPa; the tensile performance test result is: the elongation is 319%, and the breaking strength is 8.63kPa .

8) Other conditions are the same as 1), and the amount of crosslinking agent is 0.1% (mole percentage) of the monomer concentration. The obtained composite hydrogel did not yield during the compression test. When the compression ratio was 95%, the compressive strength was 15 MPa; the tensile performance test results were: the elongation was 214%, and the breaking strength was 82 kPa. And its comparative example, the PAA gel yields when the compression ratio is 83.8%, and the compressive strength is only 0.42MPa; the tensile performance test results are: the elongation is 342%, and the breaking strength is 8.61kPa.

9) Other conditions are the same as 1), and the amount of crosslinking agent is 0.3% (molar percentage) of the monomer concentration. The obtained composite hydrogel yielded when the compression ratio was 90%, and the fracture strength was 6.6MPa. The tensile property test results are: the elongation is 199%, the breaking strength is 55.3kPa, and the modulus of elasticity is 28.4kPa. And in its comparison example, PAA gel yields when the compression ratio is 92.3%, and the breaking strength is only 3.78MPa; It is 21.7kPa.

Embodiment 2: Preparation of PAA composite hydrogel with jellyfish middle glue layer as scaffold by chemical method

The acquisition of the gelatinous layer block in jellyfish is the same as in Example 1. Then soak the jellyfish medium glue layer block in a certain concentration of acrylic acid solution (crosslinking agent) for 24 hours to soak completely, then add an appropriate amount of ammonium persulfate/sodium bisulfite as the initiation system, add N, N'-methylene The base bisacrylamide is used as a cross-linking agent, and the cross-linking is polymerized by standing at room temperature. After a period of time, a composite hydrogel is obtained. The obtained composite hydrogel also has superior properties similar to the gel obtained by the irradiation method. The compression performance test was performed on it. When the compression ratio was 95%, its compressive strength was above 10MPa; it was stretched Performance test, the elongation rate is above 300%.

<Comparative Example 3>

The operation is the same as in Example 2, except that instead of using the jellyfish skin glue block, the system with the same concentration of AA, ammonium persulfate/sodium bisulfite and N, N-methylenebisacrylamide is placed in a water bath at 40°C Reacted in medium for 6h to obtain PAA ordinary gel, its strength and toughness are far inferior to the composite hydrogel obtained in Example 2. Most samples can be easily broken by hand. For example, when the monomer concentration is 3M, the compression performance test is performed on it. Yield occurs when the compression ratio is 87%, and its breaking strength is 2.34MPa.

Embodiment 3: Irradiation method prepares the PAM (polyacrylamide) composite hydrogel with jellyfish middle glue layer as scaffold

The acquisition of the jellyfish mesogelatin block used is the same as in Example 1. Soak the treated jellyfish mesogelatin block in a certain concentration of acrylamide solution (cross-linking agent) for 24 hours to make the soaking complete. Then the gel layer in the jellyfish that has been immersed is removed from the soaking liquid, and irradiated for a certain period of time with ⁶⁰ Co-γ rays (average dose rate 10kGy/h), so that the monomers are cross-linked and polymerized, and under the same conditions of concentration and irradiation time, the obtained The PAM composite hydrogel, whose hardness is higher than that of the PAA composite hydrogel, was tested for its compression performance, and they yielded at a lower compression ratio, and their fracture strength was about 15MPa. At the same time, this type of gel also has good tensile properties, and its elastic modulus is tens or even hundreds of kilopascals.

<Comparative example 4>

The AM solution soaked in jellyfish was subpackaged with penicillin vials, and irradiated under the same conditions as <Example 4> to obtain PAM gel. Its compressive performance is tested, and it is found that its strength is not as good as that of the composite hydrogel obtained in Example 3. It was tested for tensile properties, and its tensile modulus was found to be several kilopascals.

Example 4: Preparation of PAA composite hydrogel with sea cucumber body as scaffold by irradiation method

Soak the dried sea cucumber bought in the market in deionized water to make it fully swell, remove the skin, and cut the middle part into a shape similar to the collagen in jellyfish. Soak the processed sea cucumber body in a certain concentration of AA solution (cross-linking agent) for 24 hours to make the soaking complete. Then remove the soaked sea cucumber body from the soaking liquid, and irradiate it with ⁶⁰ Co-γ rays (average dose rate 10kGy/h) for a certain period of time to cross-link and polymerize the monomers in it to obtain a composite hydrogel with better strength and toughness , after testing its compression performance, the water content of the composite gel is higher than that of the jellyfish-based hydrogel. When the acrylic acid concentration is 2M and the irradiation time is 2 hours, the compression performance test is carried out. When the ratio is 92%, the breaking strength is 23MPa.

<Comparative example 5>

The AA soaking solution of the sea cucumber body was divided into vials of penicillin and irradiated under the same conditions as in Example 4 to obtain a PAA gel. Its compression performance was tested, and its strength was not as good as that of the composite hydrogel obtained in Example 4, but close to the strength of the hydrogel obtained by the method of <Comparative Example 1>.

<Comparative example 6>

The sea cucumber body was not soaked in the monomer solution, and was irradiated with ⁶⁰ Co-γ rays for the same time as the composite hydrogel. It was found that the sea cucumber body basically kept the original shape.

Compared with other hydrogels, the composite hydrogel with biological tissue as the scaffold provided by the present invention has significant advantages, which are reflected in the following aspects:

(1) Regular structure. Direct use of biological tissue with a regular structure as a network of hydrogels. The hydrogels based on such regular templates have the unattainable regularity in the structure of hydrogels synthesized by other methods.

(2) Good biocompatibility and more environmentally friendly. Using biological tissue as a scaffold for hydrogel is completely biocompatible and greener and more environmentally friendly than hydrogels obtained by other pure chemical methods. Especially when the irradiation method is used for cross-linking polymerization, substantially no chemical residues can be achieved. If biocompatible monomers are selected and cross-linked and polymerized by irradiation method, a "green hydrogel" with excellent mechanical properties that is completely biocompatible, non-toxic and harmless to the human body can be obtained. There are application prospects.

(3) The synthesis condition requirement is low, and the operation is simple. In the present invention, whether the composite hydrogel is prepared by chemical method or irradiation method, harsh synthesis conditions are not required, and it can be obtained at room temperature and in air.

(4) It is convenient to prepare samples of various shapes. Because the biological tissue is cut before the hydrogel is prepared, the experimenter can cut the organism into various shapes as needed, and then introduce synthetic polymers into it to form a composite gel of that shape. This advantage is also not available in other hydrogels.

(5) Wide application range and diverse sample types. As mentioned above, as long as the biological tissue has a regular three-dimensional network structure, it can be used as a scaffold; as long as it can penetrate into the biological tissue and can be polymerized in an appropriate way, it can be selected as the monomer for the preparation of the chemical network. Therefore, there are various types of composite hydrogels.

(6) Low cost. Because the raw materials used in the preparation of the present invention are readily available and the method is simple, the cost of obtaining the composite hydrogel of the present invention is very low.

Just because the composite hydrogel of this aspect has the above advantages, the composite hydrogel of the present invention can be used to produce artificial biological tissues, such as artificial tendons, artificial ligaments, artificial meniscal cartilage, artificial hearts or artificial joints.

The present invention has been described in detail above through the preferred embodiments and examples of the present invention, but without departing from the spirit and scope defined by the appended claims of the present invention, those skilled in the art can make these implementations Various changes and changes can be made to the mode and embodiment, that is to say, these changes and changes also belong to the concept scope of the present invention.

Claims (26)

1. composite aquogel, comprise as the bio-tissue of support and be distributed in macromolecular chain chemical compound in the described support, wherein, described bio-tissue derives from sea mollusk with ordered structure or tissue or the organ of terraria, and described macromolecular chain chemical compound forms by polywater soluble monomers in aqueous solution.

2. composite aquogel according to claim 1, wherein, described bio-tissue is the Stichopus japonicus body with collagen part in the Rhopilema esculenta of ordered structure or peeling.

3. composite aquogel according to claim 1, wherein, described monomer is selected from: neutral monomer, anionic monomer or cationic monomer.

4. composite aquogel according to claim 3, wherein, described neutral monomer is acrylamide or derivatives thereof, N-vinylpyrrolidone, hydroxy ethyl methacrylate or vinyl methyl ether.

5. composite aquogel according to claim 3, wherein, described anionic monomer is acrylic acid or derivatives thereof .beta.-methylacrylic acid or 2-acrylamide-2-methyl propane sulfonic.

6. composite aquogel according to claim 5, wherein, described anionic monomer is the acrylic propane sulfonic acid.

7. composite aquogel according to claim 3, wherein, described cationic monomer is methacryl ethyoxyl aliquat or vinylpyridine.

8. each described composite aquogel according to claim 1-7 wherein, also comprises the water-soluble cross-linker that is complementary with described monomer in described aqueous solution.

9. composite aquogel according to claim 8, wherein, described water-soluble cross-linker is selected from N, N '-methylene-bisacrylamide, ethylene glycol, Polyethylene Glycol, succinic acid or adipic acid.

10. method for preparing composite aquogel, comprise: will be immersed in as the bio-tissue of support in the aqueous solution that is dissolved with water-soluble monomer, described water-soluble monomer is diffused in the described bio-tissue, then make described polymerisation to form the macromolecular chain chemical compound that interts in described bio-tissue, thereby obtain described composite aquogel, wherein, described bio-tissue derives from sea mollusk with ordered structure or tissue or the organ of terraria.

11. method according to claim 10, wherein, described bio-tissue is the Stichopus japonicus body with collagen part in the Rhopilema esculenta of ordered structure or peeling.

12. method according to claim 10, wherein, described water-soluble monomer is selected from: neutral monomer, anionic monomer or cationic monomer.

13. method according to claim 12, wherein, described neutral monomer is acrylamide or derivatives thereof, N-vinylpyrrolidone, hydroxy ethyl methacrylate or vinyl methyl ether.

14. method according to claim 12, wherein, described anionic monomer is acrylic acid or derivatives thereof .beta.-methylacrylic acid or 2-acrylamide-2-methyl propane sulfonic.

15. method according to claim 14, wherein, described anionic monomer is the acrylic propane sulfonic acid.

16. method according to claim 12, wherein, described cationic monomer is methacryl ethyoxyl aliquat or vinylpyridine.

17. method according to claim 10, wherein, also comprise the water-soluble cross-linker that is complementary with described monomer in described aqueous solution, and wherein said water-soluble mono bulk concentration is 0.5-4M, described crosslinker concentration is the 0-5.0% of described monomer molar percentage ratio.

18. method according to claim 17, wherein, described water-soluble cross-linker is selected from N, N '-methylene-bisacrylamide, ethylene glycol, Polyethylene Glycol, succinic acid or adipic acid.

19. each described method according to claim 10-18 wherein, forms described macromolecular chain chemical compound by irradiation method in described bio-tissue.

20. method according to claim 19, wherein, described irradiation method comprises the high-energy radiation source of adopting ⁶⁰The high-power electron beam that the gamma-rays that Co produces or electron accelerator produce is implemented irradiation, so that described water-soluble monomer and/or described water-soluble cross-linker in described support polymerization crosslinking occur.

21. method according to claim 20 wherein, is adopting the high-energy radiation source to be ⁶⁰Irradiation dose when the gamma-rays that Co produces prepares composite aquogel is 5-60kGy.

22. each described method according to claim 10-18 wherein, forms described macromolecular chain chemical compound by chemical method in described bio-tissue.

23. method according to claim 22, wherein, described chemical method comprises by adding initiator in described aqueous solution, cause the described monomer generation polymerization in the described biological tissue body under 0-40 ℃.

24. method according to claim 23, wherein, described initiator is APS/NaHSO ₃System.

25. according to claim 1-9 each described composite aquogel or according to claim 10-24 in the application of composite aquogel in preparation artificial bio-membrane tissue that obtain of each described method.

26. application according to claim 25, wherein, described artificial bio-membrane's tissue is selected from: artificial tendon, prosthetic ligament, artificial meniscal cartilage, artificial heart or artificial joint.

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